Introducer sheath and methods of making

ABSTRACT

An introducer sheath and methods of making the introducer sheath are described. The introducer sheath may include a hub portion and a tubular portion. The hub portion may include a substantially non-planar valve portion in a relaxed state. The valve portion may include an aperture configured to receive a medical device. A hub portion may be formed using a forming device. An aperture may be formed through a distal surface of the valve portion. A valve portion may be formed in a cap defining a cavity sized to elastically receive a proximal end of the hub portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/427,306, entitled “Introducer Sheath”, filed Jun. 28, 2006and which claims the benefit of U.S. Provisional Patent Application Ser.No. 60/695,602, entitled “Introducer Sheath”, filed Jun. 30, 2005, eachof the preceding are incorporated herein by reference in its entirety.This application relates to U.S. patent application Ser. No. 11/427,301,entitled “Modular Introducer and Exchange Sheath”, and filed Jun. 28,2006, which claims the benefit of U.S. Provisional Patent ApplicationsSer. No. 60/695,464, entitled “Modular Introducer Sheath”, and filedJun. 30, 2005 and U.S. patent application Ser. No. 11/767,947, filedJun. 25, 2007, and entitled “Expandable Introducer Sheath to PreserveGuidewire Access”, which is a continuation in part of U.S. patentapplication Ser. No. 11/427,308, filed Jun. 28, 2006, and entitled“Expandable Introducer Sheath”, each of the proceeding are incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates generally to medical devices and methods.More specifically, embodiments of the invention relate to introducersheaths and methods of making.

2. The Relevant Technology

A wide variety of sheaths have been developed for use in medicalprocedures. Sheaths are often used, for example, to access a vessel orartery to allow a surgical procedure to be performed. Sheaths are alsoused for medical procedures that utilize catheters such as, angioplastyor stenting. In practice, the introducer sheath is generally insertedinto the patient's vasculature using the modified Seldinger technique.In the Seldinger technique, a needle is first inserted into the vesseland a guidewire then follows through the needle. Next, the needle isremoved and a sheath/dilator combination is advanced over the guidewire.The dilator expands the puncture in the vessel to a size suitable toreceive the distal end of an introducer sheath. After the distal end ofthe sheath is disposed within the vessel, the dilator and guidewire areremoved, thereby allowing access to the vessel lumen or other body lumenvia the inserted introducer sheath.

Conventionally, introducer sheaths are formed of three or morecomponents that require assembly: a sheath portion, a hub, and ahemostasis valve disposed within the hub. A suitable example of such anassembly is shown in U.S. Pat. No. 5,807,350, which shows an introducersheath having a construction similar to that described above, theentirety of which is hereby incorporated by reference.

Sheaths such as that described above are generally constructed ofmultiple pieces that must be assembled to form the sheath. Because thesheath is assembled from separate components, it is often difficult toalign the lumen of the distal sheath portion with the lumen of the hub.As a result, additional time must be taken during manufacture to ensurealignment thereby leading to increased costs.

In some instances, the hub at the proximal end of the introducer sheathmay be overmolded over the elongated sheath portion. While overmoldingmay produce a stronger sheath, there is the possibility of damaging aportion of the introducer sheath during the overmolding process. Inaddition to the cost of the overmolding process, the entire introducersheath would then have to be discarded. There is a therefore a need fora new introducer sheath having lower manufacturing costs.

BRIEF SUMMARY OF THE INVENTION

These and other limitations may be overcome by embodiments of thepresent invention, which relates generally to medical devices andmethods of use and in particular to introducer sheaths. Embodiments ofthe invention may provide several designs and methods of manufacture ofan improved introducer sheath.

An embodiment of an introducer sheath is described. The introducersheath includes an elongate tubular portion having a longitudinal axis.The elongate tubular portion is elastically deformable about thelongitudinal axis. The introducer sheath includes a hub portion havingproximal end and a distal end. The proximal end is substantially widerthan the distal end and the distal end secured to the elongate tubularportion. The introducer sheath includes a valved cover elasticallysecured over the proximal end of the hub portion. The valved coverdefines a non-planar outer surface in a relaxed state. The outer surfacedefines an aperture configured to receive a medical device.

In some embodiments, the hub portion and the elongate tubular portionare formed as a unitary member. The outer surface, in furtherembodiments, is substantially concave in the relaxed state. In stillfurther embodiments, the aperture includes a sealing surface. Thesealing surface, in yet further embodiments, is not generally parallelabout a longitudinal axis through the aperture in the relaxed state.

In some embodiments, the sealing surface is configured to form a sealbetween the medical device and the hub in a deformed state. Theaperture, in further embodiments, is tapered. In still furtherembodiments, the aperture has a diameter that increases with distancefrom the outer surface.

An embodiment of a method for making an introducer sheath assembly isdescribed. The method includes forming a cap having a top portion and asidewall portion defining a cavity. The top portion includes a valvesecured thereto. A proximal end of a hub portion is inserted into thecavity. The hub portion includes an elongate tubular portion secured toa distal end thereof.

In some embodiments, inserting the proximal end of a hub portion intothe cavity comprises elastically deforming the cap. Forming the cap, infurther embodiments, includes forming the top portion and sidewallportion and removing a portion of the top portion to form the valve.

An upper surface of the top portion, in some embodiments, has a concaveshape. In further embodiments, removing a portion of the top portion toform the valve includes elastically deforming the top portion todecrease a concavity thereof and removing a portion of the elasticallydeformed top portion to form the valve.

In some embodiments, the valve includes an aperture having a taperedshape when the top portion is in an undeformed state. The aperture, infurther embodiments, narrows with distance from the hub portion.

The sidewall portion, in some embodiments, extends from a lower surfaceof the top portion. Elastically deforming the top portion to decrease aconcavity thereof, in further embodiments, includes positioning anurging member within the cavity. In still further embodiments, theurging member comprises a planar upper surface engaging a lower surfaceof the top portion when the urging member is positioned within thecavity.

In some embodiments, one of an outer surface of the hub portion and aninner surface of the sidewall portion defines a circumferential grooveand the other of the outer surface of the hub portion and the innersurface of the sidewall portion includes a circumferential lip. Thecircumferential groove, in further embodiments, is positioned to receivethe circumferential lip when the hub portion is positioned within thecavity. In still further embodiments, the inner surface of the sidewallportion is cylindrical.

An embodiment of an assembly is described. The assembly includes anelongate tubular portion having a longitudinal axis. The elongatetubular portion is elastically deformable about the longitudinal axis.The assembly includes a hub portion having proximal end and a distalend. The proximal end is substantially wider than the distal end and thedistal end is secured to the elongate tubular portion. The hub portionand elongate tubular portion define a lumen. The assembly includes a caphaving a top portion and a sidewall portion defining a cavity sized toelastically receive a portion of the hub portion. The cap defines avalve in fluid communication with the lumen and is configured to receivea medical device.

In some embodiments, one of an outer surface of the hub portion and aninner surface of the sidewall portion defines a circumferential grooveand the other of the outer surface of the hub portion and the innersurface of the sidewall portion comprises a circumferential lip. Thecircumferential groove, in further embodiments, is positioned to receivethe circumferential lip when the hub portion is positioned within thecavity. An upper surface of the top portion, in still furtherembodiments, has a concave shape and the sidewall portion extends from alower surface of the top portion.

The sheaths disclosed herein can be used with various medical devices.In one configuration, the sheath can be used in combination with avessel closure device, such as those shown in U.S. Pat. No. 6,197,042and pending U.S. patent application Ser. No. 10/638,115 filed Aug. 8,2003 entitled “Clip Applier and Methods,” each of these assigned to acommon owner and herein incorporated in their entireties by reference.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above-recited and other advantagesand features of the invention are obtained, a more particulardescription of the invention briefly described above will be rendered byreference to specific embodiments thereof which are illustrated in theappended drawings. Understanding that these drawings depict only typicalembodiments of the invention and are not therefore to be consideredlimiting of its scope, the invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1A is a plan view of an exemplary embodiment of an introducersheath in accordance with the present invention;

FIG. 1B illustrates a cross-sectional view of the sheath in FIG. 1A andillustrates a valve disposed in the sheath's hub and an alignmentmember;

FIG. 1C is a cross-sectional view taken along line 1C-1C of the sheathof FIG. 1A in accordance with the present invention;

FIG. 2A illustrates a cross-sectional view of another sheath inaccordance with the present invention;

FIG. 2B is cross-sectional view of an alternative embodiment of thesheath of FIG. 2A illustrating the geometric features formed within wallof the sheath in accordance with the present invention;

FIG. 2C is a cross-section view of a portion of an another alternativeembodiment of the sheath of FIG. 2A in accordance with the presentinvention;

FIG. 3A is a plan view of an alternative embodiment of a sheath inaccordance with the present invention;

FIG. 3B is a cross-sectional view of the sheath of FIG. 3A taken alongline 3A-3A in accordance with the present invention;

FIG. 3C illustrates a cross-sectional view of an alternative embodimentof a sheath in accordance with the present invention;

FIGS. 4A-4E illustrate cross-sectional views of an embodiment of asheath in various stages of manufacture in accordance with the presentinvention;

FIGS. 4C′ and 4D′ illustrate cross-sectional views of the embodiment ofa sheath shown in FIGS. 4A-4E in various stages of manufacture using analternative embodiment of a forming device in accordance with thepresent invention;

FIGS. 5A-5C illustrate cross-sectional views of another embodiment of asheath in various stages of manufacture in accordance with the presentinvention;

FIG. 5B′ illustrates a cross-sectional view of the embodiment of asheath shown in FIGS. 5A-5C in various stages of manufacture using analternative embodiment of a forming device in accordance with thepresent invention;

FIGS. 6A-6C illustrate cross-sectional views of a further embodiment ofa sheath in various stages of manufacture in accordance with the presentinvention;

FIGS. 7A-7C illustrate a valved cover suitable for use with a sheath inaccordance with an embodiment of the present invention;

FIGS. 8A through 8E illustrate a method for manufacturing a valved coverin accordance with an embodiment of the present invention;

FIGS. 9A through 9C illustrate an alternative method for manufacturing avalved cover in accordance with an embodiment of the present invention;

FIGS. 10A through 10C illustrate another alternative method formanufacturing a valved cover in accordance with an embodiment of thepresent invention; and

FIGS. 11A and 11B illustrate a method for using a valved cover inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION

An introducer sheath in accordance with the present invention isdescribed herein as having portions or members, though it shall beunderstood that the introducer sheath as described herein may be formedas a unitary member such that the portions or members are portions ormembers of a unitary device. Embodiments of the introducer sheath aredepicted in the drawings, which are not necessarily to scale and are notintended to limit the scope of the invention. It will be understood thatthe benefits of the present invention are not limited to applicationwith an introducer sheath. Rather, other medical devices may be modifiedbased upon the teaching contained herein such that they to can providethe identified functionality.

The introducer sheath may be formed, by way of example, using aco-extrusion process or an injection molding process or other methodthat results in a sheath formed as a unitary member. The process bywhich an introducer sheath is formed may include the use of one or morematerials. The materials can be used simultaneously, or at differentstages of the manufacturing process.

Typically, the materials used to form the introducer sheath are medicalgrade synthetics or plastics. Exemplary materials may include, but arenot limited to, flexible PVC, polyurethane, silicone, liner low-densitypolyethylene (“LLDPE”), polyethylene, high density polyethylene,(“DHPE”), polyethylene-lined ethylvinyl acetate (“PE-EVA”),polypropylene, latex, thermoplastic rubber, and the like. In someembodiments, the materials are configured to have chemical resistance,crack resistance, no toxicity, Food and Drug Administration (“FDA”)compliance, non-electrically conductive, dimensional stability, and/orbe sterilized by ethylene oxide, gamma radiation, autoclave, UV light,ozone, and the like.

In addition, the selection of materials for a particular sheath candepend on a variety of factors that include, but are not limited to, aparticular stiffness and/or flexibility of the sheath or any portion ofthe sheath, including the desired column stiffness and strength toenable insertion of the sheath, a particular shear or split strength forthe sheath or any portion of the sheath, the ability to resist kinking,and the like. For example, the material used for the tubular portion ofthe introducer sheath may be selected based on shear strength or howeasily it can be split. Further, certain features of the sheath may beformed to enhance certain characteristics. For example, a strain reliefportion may be formed to resist kinking while the elongated tubularportion may be formed to facilitate splitting.

When more than one material is used to form the sheath or to formspecific portions of the introducer sheath, the materials may beselected, in addition to the factors identified herein, on a bondstrength between the materials or on the elasticity of a particularmaterial. The bond strength, for example, may have an impact on thesplitability of the sheath or of a portion of the sheath. The bondstrength may also affect the ability of the sheath to expand withoutsplitting.

As described above, the materials of a sheath may be selected based on asplitting or shear property of the materials. One reason for thischaracteristic or property relates to use of the sheath in medicalprocedures. For example, when the sheath is used in conjunction with amedical device during a medical procedure, it may be desirable for theintroducer sheath to split or shear during insertion or retrieval of themedical device. This may occur, for example, when a vessel is closedwith a vessel closure device. The vessel closure device can be used toattach a clip that effectively seals or closes the entry to the bodylumen. As the entry or access to the body lumen is closed, the vesselclosure device can apply a force that causes the sheath to split.Embodiments of the invention thus contemplate embodiments of the sheathor of portions of the introducer sheath that facilitate splitting at theappropriate time. Further, embodiments of the sheath contemplatestructural features that relate to the ease with which a sheath splitswithout otherwise impacting the use of the sheath.

In accordance with one embodiment of the present invention, anintroducer sheath may include a hub member or hub portion having aproximal end and a distal end. The proximal end of the hub portion canbe configured to receive a flexible valve member therein. The sheathfurther includes an elongated tubular portion generally extending fromthe distal portion of the hub member. The elongated tubular portion isgenerally centered with an axis of the hub member and the lumen of thetubular portion is aligned with a lumen of the hub portion because thesheath is formed as a single integrated unit in some embodiments.Alternatively, the lumen of the tubular portion can be aligned with alumen of the hub portion, whether or not axially aligned. The aligningof the lumens can occur during manufacture, such as when the hub portionand the sheath are formed as a single integrated unit.

Referring now to FIG. 1A, there is shown an exemplary embodiment of anintroducer sheath 10. The introducer sheath 10 can include a hub portion20 having a proximal end 22 and a distal end 24, and a tubular portion30 having a proximal end 32 and a distal end 34. The cross section ofthe hub portion 20 can be generally cylindrical in nature, althoughother configurations are contemplated. Exemplary configurations orshapes may include, by way of example, oval, polygonal, elliptical, orother cross-section that can be usable for a medical device that isinsertable into a body lumen.

The elongate tubular portion 30 extends from the distal end 24 of thehub portion 20. Because the sheath 10 can be formed as a unitary member,the proximal end 32 of the tubular portion 30 can be integrally formedwith the distal end 24 of the hub portion 20. Because the sheath 10 canbe formed as a unitary member, the hub portion 20 effectivelytransitions to the tubular portion 30. Because the transition betweenthe hub portion 20 and the tubular portion 30 may introduce a naturalflex point, embodiments of the invention can optionally include a strainrelief portion 48, which smoothly transitions the tubular portion 30 ofthe sheath 10 to the hub portion 20. The strain relief portion 48 can beformed at the transition between the hub portion 20 and the tubularportion 30. More particularly, the strain relief portion 48 can bedisposed adjacent the distal end portion of the hub portion 20 andadjacent the proximal end 32 of the elongate tubular portion 30.

The strain relief portion 48 can also be configured to provideadditional support to at least the proximal end 32 of the elongatetubular portion 30 to prevent kinking at the transition zone of theproximal end 32 of the elongated portion 30 and the distal end 24 of thehub portion 20. In one embodiment, the strain relief portion 48 can beformed by gradually increasing a thickness of tubular portion 30 as thetubular portion 30 of the sheath 10 transitions to the hub portion 20 ofthe sheath. Alternatively, the strain relief portion 48 can be formedusing other structures or formations that provide, for example, supportor kink resistance to the transition from the tubular portion 30 to thehub portion 20. For instance, the strain relief portion 48 can includewebs, extensions, or other internal or external structures to increasethe strength and/or stiffness of the introducer sheath 10 at the hubportion/tubular portion transition.

With continued reference to FIG. 1A, the distal end 34 of the tubularportion 30 can also include a tapered portion 36 that facilitates entryof the introducer sheath 10, for example, into patient's vasculature orother body lumen. The tapered portion 36 may be formed after the initialforming process of the introducer sheath 10 or be formed as part of theinitial forming process. For example, the tapered portion 36 may beformed as part of the extrusion or injection molding processes.Alternatively, the tapered portion 36 may be formed by heat forming,grinding, milling, laser treatment, etching, or other known methods thatresult in a thinner wall thickness.

FIG. 1B further illustrates a cross-sectional view of the sheath 10along the line 1B. As shown, a lumen 28 extends from a proximal end 22of the hub portion 20 to the distal end 34 of the tubular portion 30.The lumen 28 can be generally uniform in cross-section over all or aportion of its length from the proximal end 22 of the hub portion 20 tothe distal end 34 of the tubular portion 30. In the illustratedconfiguration, the lumen 28 has a generally uniform cross-section alongits length along the tubular portion 30, while having a generallyuniform cross-section portion and a changing cross-section portion alongthe length of the hub portion 20. It will be understood, however, thatother cross-sectional configurations are possible so long as they canaccommodate a medical device or instrument inserted therein.

With continued reference to FIG. 1B, the proximal end 22 of the hubportion 20, within the lumen 28 and defined by the inner wall or surface52 forming the lumen 28, can also include a feature, such as a receivingfeature 26, therein, which is configured to receive a flexible valvemember 50. The valve member 50 may be inserted after the sheath 10 isformed. For instance, the receiving feature 26, such as a groove orchannel, can receive the valve member 50 and retain the same within thehub portion 20. Optionally, a retaining cap (not shown) disposedadjacent to or within the proximal end of the hub portion 20 can aid thereceiving feature 26 to retain the flexible valve member 50 within thehub portion 20. Alternatively, the valve member 50 can be integrallyformed with the hub portion 20 during the molding process of the sheath10 and as such the hub portion 20 need not include the receiving feature26.

The cooperation between the receiving feature 26, optional the retainingcap, and/or the valve member 50 result in a sealed hub portion 20.Stated another way, the valve member 50 is self sealing once it isinserted or formed in the hub portion 20 to prevent fluid escaping fromthe body lumen.

The valve member 50 can be one of a variety of different seals,including optionally being self-sealing once it is inserted into the hubportion 20. The valve member 50, for example, may have an elastomericbody, such as silicone rubber or other material as described above, withat least one slit and/or other collapsible opening formed therein toallow selective insertion and removal of medical instruments, such asguidewires, catheters, and other such devices. The collapsible openingsor other portions of the valve member 50 maintain a fluid tight sealwith or against the medical instrument. Thus, blood or other bodilyfluids are prevented from leaking out, and unwanted air is preventedfrom entering into the body. Examples of such flexible membranes orvalve members, which can be utilized with the present invention, areshown in U.S. Pat. Nos. 4,798,594, 5,176,652, and 5,453,095 theentireties of which are herein incorporated by reference.

With continued reference to FIG. 1B, illustrated is an optional portmember 42 that may be formed on the outer surface or outer wall 44 ofthe hub portion 20. The port member 42 may function as a fluid port forthe sheath 10. Thus, any fluid, such as saline or blood or medicationfor example, can be added or withdrawn through the port member 42. Theport member 42 may also be optionally or alternatively configured toalign or position any device or instrument (e.g., a vessel closuredevice, a catheter) used in conjunction with the sheath 10. The portmember 42 may be shaped to interact with an alignment mechanism on amedical device and optionally create a fluid sealed connection. Oneexemplary type of port member is a member having a luer lockconfiguration. It will be understood that other types of port canperformed the desired function.

Also formed on the outer surface or wall 44 of the hub portion 20 can bea retention recess or ring 46, as shown in FIG. 1A. The recess or ring46 may be used to secure a cap (not shown) to the sheath 10. The recessor ring 46 can have various configurations to perform the identified anddesired function. For instance, although the walls forming the recess orring 46 are illustrated as being generally parallel, the recess or ring46 can have tapered wall, curved wall, combinations of generallyparallel, tapered, or curved wall, or generally any other configurationthat would allow a cap to be secured thereto or for the recess.

It is contemplated that the wall thickness along the length of theelongate tubular portion 30 can be varied to vary mechanical propertiesof the sheath (e.g., kink resistance, stiffness, flexibility and thelike). Further, the thickness of the strain relief 40 (which can varyacross the transition between the tubular portion 30 and the hub portion20), the thickness of the hub portion 20, the diameter of the lumen ofthe tubular portion 30 and of the lumen of the hub portion 20 can alsobe varied or specifically selected.

These dimensions of the sheath 10 are often controlled and determinedduring the manufacturing process. In an injection molding process, forexample, the sheath 10 may be formed using a mold. The mold can bemachined or configured based on the desired dimensions andconfigurations of the sheath 10 as described herein. After the mold(which may include more than one part) is formed, the injection moldingprocess can begin by melting a suitable material, such as one describedabove, and then injecting the melted material into the mold, often underpressure. The mold used in the injection molding process is typicallyformed such that the molded introducer sheath can be removed after ithas cooled and such that the resulting introducer sheath has the desireddimensions and characteristics described herein. As a result, the moldedsheath 10 can be a unitary member and may not be assembled fromseparately formed parts.

Benefits of forming the introducer sheath 10 as a unitary member mayinclude reduced costs, more accurate parts (i.e. dimension control) dueto lack of assembly, as well as the ability to balance mechanicalproperties across the entire sheath 10. For example, the thickness ofthe walls of the hub portion, the tubular portion, the strain relief,the tapered portion, and/or other portions can be controlled and variedas desired.

Referring now to FIG. 1C, there is shown a cross-sectional view of thesheath 10 in accordance with the present invention along the line 1C-1Cof FIG. 1A. In particular, FIG. 2 illustrates a cross-sectional view ofthe elongate tubular portion 30 of the sheath 10. The elongate tubularportion 30 can include an outer wall 60 and an inner wall 62 therebydefining a wall thickness. Additionally, the lumen 28 may extend alongthe length of the tubular portion 30. The width or diameter of the lumen28 can vary and may depend on the intended use of the sheath 10. Becausethe hub portion 20 and the tubular portion 30 are integrally formed, thelumen 28 may be axially aligned along its length. Stated another way,the axis of the portion of the lumen 28 within the tubular portion 30can be aligned with the axis of the portion of the lumen 28 within thehub portion 20.

Generally, the outer wall, whether defined by the outer wall 60 of thetubular portion 30 or the outer wall 44 of the hub portion 20, definesthe outer surface or wall of the sheath 10. Similarly, the inner wall,whether defined by the inner wall 62 of the tubular portion 30 or theinner wall 52 of the hub portion 20, defines the inner surface or walland lumen 28 of the sheath 10.

As mentioned above, although the cross-sectional view of the tubularportion 30 is cylindrical in nature, other cross-sectional shapes(polygonal, oval, elliptical, rectangular, etc.) are within the scope ofthe invention. Further, the lumen 28 may also have an alternativecross-sectional shape other than circular. In one example, thecross-sectional shape of the tubular portion 30 and/or the lumen 28 canbe determined by the mold used in an injection molding process. Further,the cross-sectional configuration of the lumen 28 need not be the sameas that of the cross-section configuration of the tubular portion 30 asdefined by the outer wall of the tubular portion 30, and more generallythe sheath 10.

Referring now to FIG. 2A there is shown an exemplary embodiment of analternative introducer sheath in accordance with the present invention.Much of the description related to the sheath 10 may also apply to thepresent embodiment of the sheath 110, and vice versa. The alternativeembodiment of the sheath will herein be described as having portionssimilar to that as described above.

As shown in FIG. 2A, the sheath 110 can include a hub portion 120 havinga proximal end 122 and a distal end 124, and a tubular portion 130having a proximal end 132 and a distal end 134. Extending from theproximal end 122 to the distal end 134 is a lumen 128. Generally, theconfiguration of the lumen 128 and the inner wall or surface forming thelumen 128 may be different from that described with respect to lumen 28(FIG. 1B). A portion of the lumen 128 in the hub portion 120, or theinner wall or surface 152 can have a stepped configuration. The steppedconfiguration can include a first portion 154 having a first innerdiameter and a second portion 156 having a second diameter larger thanthe first diameter. This stepped configuration, or the transitionbetween the first portion 154 and the second portion 156 provides orfunctions as a stop for an inserted valve member 150.

The valve member 150 can be secure within the lumen 128 through afriction or interference fit with the inner surface or wall 152 of thehub portion 120. Alternatively, or in addition to the friction orinterference fit, the valve member 150 can be mounted within the lumen128 through adhesives, thermal or chemical bond, mechanical coupling,such as, but not limited to, the use of a groove or recess in the innersurface or wall 152, or other technique used to mount two componentstogether. In one configuration, a retaining cap 170, having a lumen 172that can receive a medical device or instrument to be inserted throughthe valve member 150 and the lumen 128, can secure the valve member 150.The proximal end 174 of the retaining cap 170 can align with, overlap,or be recessed relative to the proximal end 122 depending upon theparticular configuration of the end cap 170.

Also formed on the outer surface or wall 152 of the hub portion 120 canbe a retention recess or ring 127, as shown in FIG. 2A. The recess orring 127 may be used to secure a cap (not shown) to the sheath 10. Therecess or ring 127 can have various configurations to perform theidentified and desired function. For instance, although the wallsforming the recess or ring 46 are illustrated as being generallyparallel, the recess or ring 46 can have tapered wall, curved wall,combinations of generally parallel, tapered, or curved wall, orgenerally any other configuration that would allow a cap to be securedthereto or for the recess.

With reference to FIGS. 2A and 2B, the elongated tubular portion 130includes an outer surface or wall 160 and an inner surface or wall 162.Formed in the inner wall 162 is at least one longitudinal groove 164,and more generally a geometric pattern of grooves, channels, recesses,or other structures, that can extend along an axis parallel to axisextending through the center of the sheath, and centered within thelumen 128. With one or more longitudinal grooves 164, the longitudinalgrooves 164 can be formed in various patterns and orientations toprovide different characteristics to the tubular portion 130. It iscontemplated that additional styles and types of patterns may beutilized in accordance with the present invention. For example, one ormore longitudinal grooves 164 may form a sinusoidal pattern disposedabout the inner radius of the elongate tubular portion 130.Alternatively, the one or more longitudinal grooves 164 may beconfigured to run along a different axis than one parallel to an axisextending along the center of the sheath 10. For example, the one ormore longitudinal grooves 164 may be formed as one or more spirals asillustrated in FIG. 2C. The one or more longitudinal grooves 164 mayalso only extend partially along the length of the elongated portion130. In another embodiment, the one or more longitudinal grooves 164 mayextend beyond the tubular portion 130 and into the hub portion 120 (FIG.1A). In another example, the one or more longitudinal grooves 164 maynot extend into the tapered portion of the tubular portion 130.

Generally, it should be understood that the above describedconfiguration of the at least one groove 164 should be consideredexemplary and not limiting in any manner. It is contemplated thatadditional styles and types of patterns may be utilized in accordancewith the present invention. For instance, one configuration of thelongitudinal grooves 164 can provide increased column stiffness, whileanother configuration can provide kink resistance and/or resistance totorsional loads. Further, it should be understood that the inner wall162 could have patterns or configurations of structures other thangrooves to achieve desired configurations. For instance, and not by wayof limitation, other dents, extensions, channels, recesses, or otherstructural formations can be created upon or in the inner wall 162.

The formation of the geometric pattern of the plurality of grooves 164,for example, can be formed by machining a corresponding feature in themold and subsequently using the mold during compression molding,injection molding, blow molding, rotational molding, and/or molding orfabrication processes. As a result, the geometric pattern can beautomatically formed during the manufacturing process and no additionalsteps or acts are required to form the geometric pattern on the innerwall 162.

Referring now to FIG. 3A there is shown an exemplary embodiment of analternative introducer sheath in accordance with the present invention.Much of the description related to sheath 10 and sheath 110 may alsoapply to the embodiment of the sheath 210, and vice versa. Thealternative embodiment of the sheath will herein be described as havingportions similar to that as described above.

As shown in FIG. 3A, the sheath 210 includes a hub portion 220 having aproximal end 222 and a distal end 224. The sheath 210 further includes acomposite elongate tubular portion 230 extending from the distal end 224of the hub portion 220. In this example, the elongated portion 230 maybe generally tubular in construction and may include a proximal end 232and a distal end 234. As described above, the cross-sectional shape ofboth the elongated portion 230 and the hub portion 220 can be any shape,such as by way of example, circular, elliptical, square, polygonal, andthe like. In this example, however, the tubular portion may be compositeand can be formed from more than one material.

The sheath 210 may additionally include a feature formed within the hubportion 220 that may be configured to receive a flexible valve member(such as the valve member 50 in FIG. 1B or valve member 150 in FIG. 2A).The flexible valve member may be integrally formed into the hub portionduring the molding process of the sheath 210 or may be held within thehub portion 220 using the techniques or methods described herein.Alternatively, the hub portion 220 of the sheath 210 can be molded toprovide the elements needed to hold the valve member in place afterinsertion. The receiving feature 26 (FIG. 1B) or the steppedconfiguration illustrated in FIG. 2A are examples of features that canretain the valve member after insertion into the hub portion 220.

Turning now to the tubular portion 230, and with reference to FIGS. 3Aand 3B, at least one groove 280 may be disposed within at least aportion of the tubular portion 230, with one being shown in theillustrated configuration. This groove 280 can receive an insert 282 toprovide certain characteristics and properties to the tubular portion230. For instance, the insert 282 can provide structural stiffness orkink resistance to the tubular portion 230 and/or the introducer sheath210. The groove 280 can extend from (i) the outer surface or wall 260 tothe inner surface or wall 262, (ii) the outer surface or wall 260 towardthe inner surface or wall 262, or (iii) the inner surface or wall 262toward the outer surface or wall 260.

As shown in FIGS. 3A and 3B, the groove 280 and/or the insert 282 canextend from the tubular portion 230 to the hub portion 220. Generally,the groove 280 and/or the insert 282 can extend from a portion of thetubular portion 230 to a portion of the hub portion 220. Alternatively,the groove 280 and/or the insert 282 may be formed only in the tubularportion 230, only in the hub portion 220, or in a portion of the hubportion 220 or the tubular portion 230. In other embodiments, one ormore grooves 280 and/or inserts 282 can be formed in the sheath 210.Although reference is made to a groove, herein other geometric patternsor configurations of channels, recess, holes, or other structures formedin the sheath can be used. Further, a line or other geometric patternscored or formed in the sheath, with or without the inclusion of theinsert can function in a similar manner to the groove and insert asdescribed herein.

With continued reference to FIGS. 3A and 3B, the insert 282 can beformed in the groove 280 in a variety of manners. In one configuration,the groove 280 can be formed as part of the initial molding process. Forinstance, the sheath 210 can undergo a first injection molding processwhere the hub portion 220 and elongated portion 230 are formed as asingle unitary unit, with the groove 280 being formed at that time. Themold used to form the sheath 210 may then be adapted, such as byremoving the portion of the mold that was responsible for the groove280, and a second injection molding process may then be performed toinject a second material into the groove 280 to form the insert 282. Theinsert 282 may effectively bond to the material defining the groove 280resulting in the sheath, the sheath being a unitary member. One exampleof a molding technique that can be used to perform the above-describedprocess is an over-molding injection molding process.

It is also contemplated that the first and second injection moldingprocesses can be conducted simultaneously or within a time period ofeach other, for instance by way of an over-molding injection moldingprocess or a 2-shot injection molding process. In one configuration, amold can be manufactured and placed into an injection molding machine,wherein the first molding process can form the sheath including thegroove 280 shown in FIG. 3A and a second molding process would form thecompleted sheath by filling the groove 280 with a second material toform the insert 282, resulting in the configuration of FIG. 3B. Thus,the tubular portion 230 can be a composite. The process times can becontrolled depending upon the materials to be molded and the desiredmechanical properties.

With reference to FIG. 3B, a cross-sectional view of the elongatedportion 230 taken about line 3B-3B of FIG. 3A is illustrated. Thecross-sectional view of FIG. 3B illustrates the tubular portion 230after the groove 280 has been formed and filled with a second material,which forms the insert 282. As shown in FIG. 3B, the elongate tubularportion 230 has an outer wall 260 and an inner wall 262 thereby defininga lumen 228 as well as a wall thickness. The insert 282 is showndisposed in groove 280 thereby forming a continuous generally tubularcross-section. In one configuration, the inner wall or surface 262 ofthe elongated portion 230 typically remains smooth after the secondmaterial is injected into the groove 280 to form the insert 282.Alternatively, the inner surface 262 of the elongated portion 230 canhave one or more variations, at least one of which can be defined by theinsert 282 within the groove 280. For instance, during the process ofapplying or depositing the second material the mold defining theboundaries for the second material 282 can include the desired patternof the portion of the inner wall or surface 262 associated with theinsert 282.

As previously described above, the second material, as well as the firstmaterial, may be chosen based upon desired mechanical properties for thesheath 210. For example, it may be desirable to produce an elongatedportion 230 that is easily splitable along a portion of the interfacebetween the first and second materials or through the second material inresponse to an adequate applied force. In this case, the bond betweenthe first material and the second material can be adjusted through themanufacturing process. As previously stated, the first and secondmaterials may be selected according to the bond between the firstmaterial and the second material and on the splitability of the firstand/or second materials. For example, the thickness of the firstmaterial at the interface with the second material can be less than thethickness of the first material at other locations. This, combined witha second material that fills the groove 280 to form the insert 282 andmay have less strength than the first material, may provide a sheaththat has particular properties. For example, the tubular portion 230 maybe more likely to split along the groove 280 or along any othergeometric pattern formed on the inner wall of the tubular portion 230,whether or not filled with a second material or the insert 282. Ininstances where the geometric pattern such as the groove 280 is filledwith a second material to form the insert 282, a bond may be formedautomatically during the molding process. Alternatively, thermalbonding, chemical bonding, or other known techniques can be used tofacilitate bonding between the similar or dissimilar medical gradematerials forming the insert 282 and the remainder of the sheath 210.

As illustrated above, mechanical properties of the tubular portion maybe adjusted by forming the elongate tubular portion 230 as a compositemember. For example, if it is desirable to produce a sheath that issplitable during use, the second material and the insert 282 may beweaker than the first material, thereby forming a joint wherein thesheath may be easily split by an applied force. Alternatively, thesecond material or insert 282 can be utilized to stiffen or weaken theoverall tubular portion 230. This can be used to prevent kinking, andthe like. Alternatively, the second material or insert 282 can be usedto stiffen or weaken the overall tubular portion 230 and assist insplitting the sheath during use. For example, the second material orinsert 282 may provide stiffness and cause the tubular portion 230 tosplit at the groove or other geometric pattern in response to an appliedforce, such as the withdrawal of a medical device like a vessel closuredevice.

Although the alternative embodiment has been described with respect tospecific geometries as well as construction methods this should not beconsidered limiting in any manner. For example, it is contemplated thatthe groove 280 may be formed having many different geometric shapes andpatterns as well as lengths. Additionally, the groove may include ageometric feature formed along the length thereof, wherein the secondmaterial or insert 282 would fill into this feature, therebyinterlocking the two materials together.

FIG. 3C, for example, illustrates another configuration of the interfacebetween a first material and a second material or between the groove andan insert. In particular, the groove 280 includes sub-grooves 284 thatextend outwardly from the main portion of the groove 280. Thesesub-grooves 284 can receive or be filled with the second material thatforms the insert 282 during the injection molding process and provide amechanical connection or coupling between the two materials and betweenthe groove 280 and the insert 282. As such, the sub-grooves 284,together with the insert 282 or second material deposited therein, mayfunction as interlocking features that may mechanically tie the portionsof the tubular portion 230 together. By so doing, the two portions ofthe tubular portion 230 can be mounted or coupled together through boththe bonding of the two materials and the mechanical coupling of theinterlocking features formed in the groove 280 and the insert 282.

It will be understood that in another configuration, the insert 282 canbe formed separately from the remainder of the sheath 210. The insert282 can then be mounted or coupled to the groove 280 during subsequentprocessing. For instance, the insert 282 can be mounted or coupled tothe groove 280 using adhesives, thermal or chemical bonding, and/orother techniques to mount or couple similar or dissimilar medical gradematerials. Further, the insert 282 can mount or couple using mechanicalstructures, such as but not limited to, the interlocking features, withor without the use of adhesives, thermal or chemical bonding, and/orother techniques to mount or couple similar or dissimilar medical gradematerials.

Because the sheath can be formed by an injection molding process usingmolten or melted material, the shape of the sub-grooves 284, or othermechanical structures that facilitate mechanical coupling between twocomponents, can vary and accommodate any desired purpose. In someinstances, the formation or filling of the groove 280 with the secondmaterial to form the insert 282 may cause the first material to melt,thereby causing the two materials to bond. For example, the shape of thefeature 284 may include extensions that prevent the first material fromseparating from the second material without tearing or shearing. Thiscan strengthen the bond, in one example, between the first and secondmaterials. Further, the interlocking feature may ensure that the tubularportion shears at the groove 280 owing to the strength or lack thereofof the second material.

The at least one interlocking features illustrated in FIG. 3C can extendfrom a proximal end 232 to a distal end 234 of the tubular portion 230and/or the introducer sheath 210. It will be understood, however, thatthe at least one interlocking feature can extend only part way from thedistal end toward the proximal end, from the proximal end to the distalend, or at any location along the length of the tubular portion 130and/or the sheath 210.

In addition to the use of a second material to fill the groove 280 orother geometric pattern, it is further contemplated that more than twomaterials may be utilized to form the introducer sheath in accordancewith the present invention or that other portions of the sheath may beformed from a second material. For example, a first material may beutilized to form the hub portion and one or more materials (which mayinclude the first material) may be utilized to form the elongatedportion of the sheath. Again, the selection of materials may depend onthe end use of the sheath, properties of medical devices used with thesheath, and the like or any combination thereof. Although the presentinvention has been shown and described in accordance with specificembodiments these should not be considered limiting in any manner. Forexample, multiple materials may be utilized to form a unitary sheath inaccordance with the present invention, wherein multiple injectionmolding processes are performed simultaneously or in stages to form theunitary sheath in accordance with the present invention.

Referring generally to FIGS. 4A-4E, there is shown a system 300 formanufacturing a sheath 310 during various stages of manufacture. Theintroducer sheath 310 of this embodiment may be at least partiallyfunctionally similar to that of the introducer sheaths, 10, 110, 210previously described above and shown in FIGS. 1A-3C in most respects,wherein certain features will not be described in relation to thisembodiment wherein those components may function in the manner asdescribed above and are hereby incorporated into this alternativeembodiment described below. Like structures and/or components are givenlike reference numerals.

The introducer sheath 310 may include a hub portion 320, which includesa proximal end 322 and a distal end 324, and/or a tubular portion 330,which includes a proximal end 332 and a distal end (not shown). Thecross section of the hub portion 320 can be generally cylindrical innature, although other configurations are contemplated. The hub portion320 may include a valve portion 350. As shown in FIG. 4A, the valveportion 350 may be a portion of a surface on the distal end 324 of thehub portion 320. The valve portion 350 may include a distal surface 351.

Although not illustrated in FIGS. 4A-4E, the sheath 310 may include anoptional port member, such as the optional port member 42 shown in FIG.1B, that may be formed on the outer surface or outer wall 344 of the hubportion 320. The sheath 310 may further include a retention recess orring, such as the retention recess or ring 46 shown in FIG. 1A.

Referring specifically to FIG. 4A, the system 300 for manufacturing asheath 310 may include a first forming device 386 and/or an externalforming device 388. The first forming device 386 may include a concaveproximal end 387. The external forming device 388 may include a convexdistal end 389. For instance, the proximal end 387 of the first formingdevice 386 and/or the distal end 389 of the external forming device 388may be curved, as shown in FIG. 4A, or may come in other convex shapessuch as an inverted “V” shape and/or other shapes that are substantiallynon-parallel toward the distal end 324 of the hub portion 320.

In an injection molding process, for example, the sheath 310 may beformed using core pin as the first forming device 386 and a mold as theexternal forming device 388. The first forming device 386 and/or theexternal forming device 388 can be machined or configured based on thedesired dimensions and configurations of the sheath 310 as describedherein.

After the first forming device 386 and/or the external forming device388, which may include multiple parts, are formed (i.e. milled, lathed,etc.), the injection molding process may begin by melting a suitablematerial, such as one described above, and then injecting the meltedmaterial using the first forming device 386 and/or the external formingdevice 388, often under pressure. The external forming device 388 may beformed such that the molded introducer sheath 310 can be removed afterit has cooled and such that the resulting introducer sheath 310 has thedesired dimensions and characteristics described herein. As a result,the molded sheath 310 can be a unitary member and may not requireassembly from separately formed parts.

As shown in FIG. 4A, the valve portion 350 may be formed in a concaveshape. As shown in FIG. 4B, the valve portion 350 may have a concaveshape in a relaxed state after the sheath 310 is formed and the firstforming device 386 and/or the external forming device 388 are removed.The first forming device 386 may be removed through the lumen 328. Forexample, the sheath 310 may be sufficiently elastic to allow the firstforming device 386 to be removed through the lumen 328.

A second forming device 392 may be inserted into the hub portion 320, asshown in FIG. 4C. The second forming device 392 may be inserted throughthe tubular portion 330. The second forming device 392 may include aproximal end 393 that is substantially planar. The second forming device392 may deform the valve portion 350 from the concave shape in therelaxed state, as shown in FIG. 4B, toward a substantially planar shapein a deformed state, as shown in FIG. 4C. For example, the proximal end393 of the second forming device 392 may abut at least a portion of thedistal surface 351 of the valve member 350 to deform the valve member350. In other embodiments, the proximal end 393 of the second formingdevice 392 may vary in shape. For instance, the proximal end 393 may beconvex, square, and/or otherwise shaped. The proximal end 393 of thesecond forming device 392 may have a surface area that is substantiallythe same size as the distal surface 351 of the valve portion 350, asshown in FIG. 4C.

As shown in FIG. 4C′, an alternative embodiment of a second formingdevice 392′ may be inserted into the hub portion 320. The second formingdevice 392′ may be inserted through the tubular portion 330. The secondforming device 392′ may deform the valve portion 350 from the concaveshape in the relaxed state, as shown in FIG. 4B, toward a substantiallyplanar shape in a deformed state, as shown in FIG. 4C′. The proximal end393′ of the second forming device 392′ may have a surface area that issubstantially smaller than the distal surface 351 of the valve portion350. For example, the proximal end 393′ of the second forming device392′ may have a surface area that is approximately the same size as theaperture 398 to be formed. In another example, the proximal end of thesecond forming device 392′ may have a surface area that is approximatelythe same size as an area of the lumen 328 of the tubular portion 330. Asshown in FIG. 4D′, a blade 394 may have a dimension that isapproximately the same as a dimension of the second forming device 392′.Other sizes and/or shapes of the second forming device 392′ may be used.

As shown in FIG. 4D, an aperture 398 may be formed. The aperture 398 maybe formed while the valve portion 350 is in the deformed state.Typically, the aperture 398 may be formed after the sheath 310 hascooled. However, it may be desirable to form the aperture 398 beforeand/or during the cooling process.

The aperture 398 may be formed using a blade 394. The blade 394 mayinclude a twist drill bit, a boring bit, and/or other blades. The blade394 may remove material through at least a portion of the distal surface351 of the valve portion 350. The blade 394 may contact the secondforming device 392 during forming of the aperture 398.

The blade 394 may have a hardness that is lower than the hardness of thesecond forming device 392 and/or higher than the hardness of the valveportion 350. Having a hardness that is lower than the second formingdevice 392 may limit damage to the second forming device 392. However,other hardnesses may be selected for the blade 394, the second formingdevice 392, and/or the valve portion 350.

The blade 394 may form a substantially cylindrical aperture 398.Alternatively, the blade 394 may produce other shapes of apertures 398.Typically, the aperture 398 may be formed through a central portion ofthe distal surface 351 of the valve portion 350. For example, alongitudinal axis of the aperture 398 may be aligned with a longitudinalaxis of the hub portion 320 and/or tubular portion 330.

The aperture 398 of the valve portion 350 may provide a sealed hubportion 320. Stated another way, the aperture 398 of the valve portion350 may be self-sealing to prevent fluid escaping from the body lumen.To facilitate sealing, the aperture 398 may include a sealing surface399. The sealing surface 399 may be configured to form a seal between amedical device and the hub portion 320. The sealing surface 399, in thedeformed state, may be generally parallel to the longitudinal axis ofthe hub portion 320 and/or tubular portion 330 (i.e. the sealing surface399 maybe substantially cylindrical).

As shown in FIG. 4E, the valve portion 350 may still be generallyconcave in the relaxed state after the aperture 398 is formed. Thesealing surface 399, in the relaxed state, may be generally nonparallelto the longitudinal axis of the hub portion 320 and/or tubular portion330 (i.e. the sealing surface 399 may be substantially conic).

When in use, a medical device may be inserted through the aperture 398while the valve portion 350 is in the relaxed state. An outer surface ofthe medical device may contact at least a portion of the sealing surface399 (i.e. a proximal edge and/or other portion). When the medical devicehas been inserted approximately a desired distance, the medical devicemay be retracted. Retracting the medical device may transition the valveportion 350 from the relaxed state toward the deformed state. Forexample, the outer surface of the medical device may engage the sealingsurface 399 such that the valve portion 350 may transition toward thedeformed state.

Benefits of forming an aperture 398 in the hub portion 320 of introducersheath 310 may include reduced costs (i.e. assembly costs for a separateflexible valve member), more accurate parts (i.e. dimension control) dueto lack of assembly, as well as the ability to balance mechanicalproperties across the entire sheath 310.

Referring generally to FIGS. 5A-5C, there is shown a system 400 formanufacturing a sheath 410 during various stages of manufacture. Theintroducer sheath 410 of this alternative embodiment may be at leastpartially functionally similar to that of the introducer sheaths, 10,110, 210, 310 previously described above and shown in FIGS. 1A-4E inmost respects, wherein certain features will not be described inrelation to this embodiment wherein those components may function in themanner as described above and are hereby incorporated into thisalternative embodiment described below.

For example, although not illustrated in FIGS. 5A-5C, the sheath 410 mayinclude an optional port member, such as the optional port member 42shown in FIG. 1B, that may be formed on the outer surface or outer wall444 of the hub portion 420. In another example, the sheath 410 mayfurther include a retention recess or ring, such as the retention recessor ring 46 shown in FIG. 1A. Like structures and/or components are givenlike reference numerals.

The introducer sheath 410 may include a hub portion 420, which includesa proximal end 422 and a distal end 424, and/or a tubular portion 430,which includes a proximal end 432 and a distal end 434. The crosssection of the hub portion 420 can be generally cylindrical in nature,although other configurations are contemplated. The hub portion 420 mayinclude a valve portion 450. As shown in FIG. 5A, the valve portion 450may be a portion of a surface on the distal end 424 of the hub portion420. The valve portion 450 may include a distal surface 451.

Referring specifically to FIG. 5A, the system 400 for manufacturing asheath 410 may include a forming device 486 and/or an external formingdevice 488. The forming device 486 may include a substantially planarproximal end 487. The forming device 486 may further be flared towardthe proximal end 487. The external forming device 488 may include asubstantially planar distal end 489. The external forming device 488 mayfurther be flared internally toward the distal end 489. In an injectionmolding process, for example, the sheath 410 may be formed using corepin as the forming device 486 and a mold as the external forming device488. The forming device 486 and/or the external forming device 488 canbe machined or configured based on the desired dimensions andconfigurations of the sheath 410 as described herein.

After the forming device 486 and/or the external forming device 488,which may include multiple parts, are formed (i.e. milled, lathed,etc.), the injection molding process may begin by melting a suitablematerial, such as one described above, and then injecting the meltedmaterial using the forming device 486 and/or the external forming device488, often under pressure.

As shown in FIG. 5A, the valve portion 450 may be formed in asubstantially planar shape. The sheath 410 may be formed in a deformedrather than a relaxed state. For example, the geometry of the formingdevice 486 and/or external forming device 488 may determine whether thesheath 410 is formed in a relaxed or a deformed state. In the presentexample, the sheath 410 may be formed in a deformed state because theforming device 486 and/or external forming device 488 are flared towardtheir proximal end 487 and/or distal end 489, respectively. The flaringmay generate internal stresses within the sheath 410 to deflect thevalve portion 450 toward a substantially concave shape in a relaxedstate.

As shown in FIG. 5B, an aperture 498 may be formed. The aperture 498 maybe formed while the valve portion 450 is in the deformed state. Theaperture 498 may be formed using a blade 494 that may remove materialthrough at least a portion of the distal surface 451 of the valveportion 450. The blade 494 may contact the forming device 486 duringforming of the aperture 498. The blade 494 may have a hardness that islower than the hardness of the forming device 486 and/or higher than thehardness of the valve portion 450.

The blade 494 may form a substantially cylindrical aperture 498.Alternatively, the blade 494 may produce other shapes of apertures 498.Typically, the aperture 498 may be formed through a central portion ofthe distal surface 451 of the valve portion 450. For example, alongitudinal axis of the aperture 498 may be aligned with a longitudinalaxis of the hub portion 420 and/or tubular portion 430.

The aperture 498 of the valve portion 450 may provide a sealed hubportion 420. Stated another way, the aperture 498 of the valve portion450 may be self-sealing to prevent fluid escaping from the body lumen.To facilitate sealing, the aperture 498 may include a sealing surface499. The sealing surface 499 may be configured to form a seal between amedical device and the hub portion 420. The sealing surface 499, in thedeformed state, may be generally parallel to the longitudinal axis ofthe hub portion 420 and/or tubular portion 430 (i.e. the sealing surface499 maybe substantially cylindrical).

As shown in FIG. 5B′, an alternative embodiment of a forming device 486′may be used to form the sheath 410. The forming device 486′ may be acombination of the forming device 486 and external forming device 488 ofthe embodiment shown in FIG. 5A. However, in this alternativeembodiment, an aperture forming member 490′ may be added to the formingdevice 486′ to form the aperture 498 in the valve portion 450 of thesheath 410. The aperture forming member 490′ may eliminate the need fora blade 494 to form the aperture 498.

An aperture forming member 490′ may be used in other embodiments. Forexample, an aperture forming member 490′ may be used with the system 400for manufacturing a sheath 410. In the system 400, the aperture formingmember 490′ may be shaped to generally match the shape of the aperture498 in the relaxed shape. The use of an aperture forming member 490′ inthe system 300 may eliminate the need for a second forming device 392and/or a blade 394.

In the present example, the aperture forming member 490′ may besubstantially cylindrically shaped to form a substantially cylindricalshaped aperture 498. However, other shapes may be used.

As shown in FIG. 5C, the valve portion 450 may still be generallyconcave in the relaxed state after the aperture 498 is formed (i.e. bythe blade 494 or by the aperture forming member 490′). The sealingsurface 499, in the relaxed state, may be generally nonparallel to thelongitudinal axis of the hub portion 420 and/or tubular portion 430(i.e. the sealing surface 499 may be substantially conic). The valveportion 450 may have a concave shape in a relaxed state after the sheath410 is formed and the forming device 486 and/or the external formingdevice 488 or the forming device 486′ with an aperture forming member490 are removed.

Referring generally to FIGS. 6A-6C, there is shown a system 500 formanufacturing a sheath 510 during various stages of manufacture. Theintroducer sheath 510 of this alternative embodiment may be at leastpartially functionally similar to that of the introducer sheaths, 10,110, 210, 310 previously described above and shown in FIGS. 1A-5C inmost respects, wherein certain features will not be described inrelation to this embodiment wherein those components may function in themanner as described above and are hereby incorporated into thisalternative embodiment described below.

For example, although not illustrated in FIGS. 6A-6C, the sheath 510 mayinclude an optional port member, such as the optional port member 42shown in FIG. 1B, that may be formed on the outer surface or outer wall544 of the hub portion 520. In another example, the sheath 510 mayfurther include a retention recess or ring, such as the retention recessor ring 46 shown in FIG. 1A. Like structures and/or components are givenlike reference numerals.

The introducer sheath 510 may include a hub portion 520, which includesa proximal end 522 and a distal end 524, and/or a tubular portion 530,which includes a proximal end 532 and a distal end 534. The crosssection of the hub portion 520 can be generally cylindrical in nature,although other configurations are contemplated. The hub portion 520 mayinclude a valve portion 550. As shown in FIG. 6A, the valve portion 550may be a portion of a surface on the distal end 524 of the hub portion520. The valve portion 550 may include a distal surface 551.

Referring specifically to FIG. 6A, the system 500 for manufacturing asheath 510 may include a forming device 586 and/or an external formingdevice 588. The forming device 586 may include a substantially planarproximal end 587. The forming device 586 may further include asubstantially cylindrical shape toward the proximal end 587. Theexternal forming device 588 may include a substantially planar distalend 589. The external forming device 588 may further include asubstantially cylindrical internal shape toward the distal end 589. Inan injection molding process, for example, the sheath 510 may be formedusing core pin as the forming device 586 and a mold as the externalforming device 588. The forming device 586 and/or the external formingdevice 588 can be machined or configured based on the desired dimensionsand configurations of the sheath 510 as described herein.

After the forming device 586 and/or the external forming device 588,which may include multiple parts, are formed (i.e. milled, lathed,etc.), the injection molding process may begin by melting a suitablematerial, such as one described above, and then injecting the meltedmaterial using the forming device 586 and/or the external forming device588, often under pressure.

As shown in FIG. 6A, the valve portion 550 may be formed in asubstantially planar shape. Because the forming device 586, in thepresent example, may be unflared (i.e. substantially cylindrical) towardthe proximal end 587 and/or have a substantially planar proximal end587, the valve portion 550 may remain substantially planar in therelaxed state. A manufacturing process may be used to facilitatetransitioning the valve portion 550 toward a substantially concave shapein the relaxed state. In one example, an interim stress differential maybe created in and/or around the valve portion 550. The interim stressdifferential may be created before the formed sheath 510 hassubstantially cooled. The interim stress differential may be created by,for example the temperatures of the molds near the valve portion 550,the thickness along the valve portion 550, other aspects of the moldand/or valve portion may be varied, or combinations thereof.

As shown in FIG. 6B, an aperture 598 may be formed. The aperture 598 maybe formed before, during, or after a manufacturing processes is used tofacilitate transitioning the valve portion 550 toward a substantiallyconcave shape in the relaxed state. The aperture 598 may be formed usinga blade 594 that may remove material through at least a portion of thedistal surface 551 of the valve portion 550. The blade 594 may contactthe forming device 586 during forming of the aperture 598.

The blade 594 may form a substantially cylindrical aperture 598.Alternatively, the blade 594 may produce other shapes of apertures 598.

The aperture 598 of the valve portion 550 may provide a sealed hubportion 520. Stated another way, the aperture 598 of the valve portion550 may be self sealing to prevent fluid escaping from the body lumen.To facilitate sealing, the aperture 598 may include a sealing surface599. The sealing surface 599 may be configured to form a seal between amedical device and the hub portion 520. The sealing surface 599, in thedeformed state, may be generally parallel to the longitudinal axis ofthe hub portion 520 and/or tubular portion 530 (i.e. the sealing surface599 maybe substantially cylindrical).

An alternative embodiment of a forming device (not shown), similar tothe forming device shown in FIG. 5B′ may be used to form the sheath 510.The forming device may be a combination of the forming device 586 andexternal forming device 588 of the embodiment shown in FIG. 6A. Forexample, the forming device may include a substantially planar exteriorproximal end and/or interior distal end, similar to the forming device486′ shown in FIG. 5B′. The forming device may further include asubstantially cylindrical shape toward the exterior proximal end and/orthe interior distal end rather than being flared toward the exteriorproximal end 487 and/or interior distal end 489 of the forming device486′ shown in FIG. 5B′.

As shown in FIG. 6C, the valve portion 550 may still be generallyconcave in the relaxed state after the aperture 598 is formed (i.e. bythe blade 594 or by an aperture forming member).

Although the present examples describe manufacturing the sheaths 310,410, 510 as unitary members, the hub portions 320, 420, 520 may bemanufactured separately from the tubular portions 330, 430, 530. Forexample, the hub portion 320, 420, 520 may be manufactured separately asgenerally described above and then joined with a tubular portion 330,430, 530. Furthermore, although the present example describes aninjection molding process, other forming processes may be used to fromthe hub portion 320, 420, 520 and/or tubular portion 330, 430, 530. Forinstance, it is contemplated that a lost wax process and/or othersuitable process may be used to form the tubular portion 330, 430, 530and/or hub portion 320, 420, 520 having a substantially concave valveportion 350, 450, 550 in a relaxed state.

Referring to FIGS. 7A through 7C, in an alternative embodiment anintroducer sheath, such as is illustrated in FIGS. 1A through 3C may beadapted to receive a valved cover 700. The cover 700 may be sized, forexample to cover a portion of the hub 20 proximate the proximal end 22of the introducer sheath of FIGS. 1A through 1C. The cover 700 maylikewise be positioned over a portion of the proximal end 122 of the hub120 of FIGS. 2A through 2C or the proximal end 222 of the hub 220 of theintroducer sheath of FIGS. 3A through 3C. In embodiments where thevalved cover 700 is used the flexible valve member 50 and correspondingreceiving feature 26 may be omitted. Alternatively, one or both of thevalve member 50 and receiving feature 26 may be retained in order toprovide a redundant seal or to provide the option of positioning a sealmember 50 in the receiving feature 26 if desired. Likewise, with respectto FIGS. 2A through 2C, the seal member 150 may be omitted or retainedwhere a valved cover 700 is used.

Referring specifically to FIGS. 7A and 7B, the valved cover 700 mayinclude an upper portion sized to cover the proximal end 22, 122, 222 ofthe hub portion 20, 120, 220. The upper portion 702 may include an outersurface 704 that is exposed when the valved cover 700 is secured to thehub portion 20, 120, 220. The outer surface 704 preferably has aninverted or concave shape. For example, the outer surface 704 may have aspherical or conical shape. A sidewall portion 706 may secure to theupper portion 702. For example, the sidewall portion 706 may extendaround a perimeter of the upper portion 702 such that the upper portionand sidewall portion 706 define a cavity sized to receive the proximalend 22, 122, 222 of the hub portion 20, 120, 220. Alternatively, thecavity may be sized to receive the proximal end 22, 122, 222 of the hubportion 20, 120, 220 only after elastic deformation thereof. In theillustrated embodiment, the sidewall portion 706 defines a cylindricalinner surface 710. However, the inner surface 710 may be shaped toconform to whatever shape is had near the proximal end 22, 122, 222 ofthe hub portion 20, 120, 220.

A retaining member 712 may project inwardly from the inner surface 710and engage the hub portion 20, 120, 220 to resist removal thereof. Inthe illustrated embodiment, the retaining member 712 is embodied as alip extending circumferentially around the inner surface 710. The lip orretaining member 712 may be sized to fit within the retention recess, orring, 46 in the embodiments of FIGS. 1A through 1C or within theretention recess, or ring, 127 in the embodiments of FIGS. 2A through3C. In an alternative embodiment, the lip or retaining member 712 may bereplaced by a circumferential groove formed in the inner surface 810 ofthe sidewall 706 and sized to receive a ridge extendingcircumferentially around the hub portion 20, 120, 220 near the proximalend 22, 122, 222.

The valve cover 700 may be formed of an elastic material, such as anelastic, biocompatible polymer. The sidewall 706 and retaining member712 preferably deforms sufficiently to allow the retaining member 712 tobe passed over the proximal end 22, 122, 222 of the hub portion 20, 120,220 and into engagement with the retention recess, or ring, 46.

A valve 714 may be formed in the top portion 702. The valve 714 may besized to receive a catheter or other slender instrument for threadingthrough the introducer sheath into the vasculature of a patient. In theillustrated embodiment, the valve 714 is embodied as an aperture 716extending through the top portion 702. Alternatively, the valve 714 maybe a valving structure secured within the aperture 716 such as by meansof overmolding, adhesive, or the like. The aperture 716 may be taperedwhen the top portion 702 is not deformed by an external force, such asan aperture 716 having a conical shape. The aperture 716 may be taperedsuch that the diameter 720 of the aperture 716 increases with distancefrom the upper surface 704 of the top portion.

Referring to FIGS. 8A through 8E, the valve 700 may be formed in the topportion 702 according to the method illustrated. As shown in FIG. 8A,the sidewall 706 and top portion 702 may be formed, such as by a moldingprocess. As is apparent in FIG. 8A, the mold 800 includes mold portions800 a, 800 b combinable to form a cavity 802 that may be filled with aliquid polymer that becomes solid through a cooling or curing process.The cavity 802 may include surfaces 804 a, 804 b positioned on eitherside of the top portion 702 of the molded valved cover 700. The surfaces804 a, 804 b may be shaped such that the upper surface 704 has aninverted or concave shape following the molding process as shown by thevalved cover 700 shown in FIG. 8B. For example, the surfaces 804 a, 804b may have a spherical shape. Alternatively, the surfaces 804 a, 804 bmay have a conical shape such that the upper surface 704 has a conicalshape.

Referring to FIG. 8C, the concavity of the upper surface 704 may then bereduced by deforming the top portion 702 prior to forming the valve 714.In the illustrated embodiment, reduction of the concavity of the uppersurface 704 is accomplished by inserting a mandrel 806 within the cavitydefined by the sidewall 706 and top portion 702. The mandrel 806 mayhave an upper surface 808 that is flat or has a radius of curvaturegreater than an undeformed radius of curvature of the lower surface 810of the top portion 702, such that as the mandrel 806 is urged againstthe lower surface 810, the concavity of the upper surface 704 isreduced.

Referring to FIG. 8D, the aperture 716 for the valve 714 may then beformed in the top portion 702, such as by means of cutting tool 812,such as a rotating drill, punch, actuated blade, or the like. Themandrel 806 may then be removed to yield a valved cover 700 such as isillustrated in FIGS. 7A and 7B. Referring to FIGS. 8C and 8D′, in someembodiments, the mandrel 806 may be embodied by a rod 814 pressedagainst the lower surface 808 during the cutting step illustrated inFIG. 8D′. For example, the rod 814 may have an upper surface 814 that ishas an area substantially smaller than the area of the lower surface 810of the top portion 702. For example, the rod 814 may have an area thatis slightly greater or smaller (e.g. ±5 to 10%) that of the aperture716.

Upon removal of the mandrel 806 or rod 814, the top portion 702 mayelastically return to its undeformed shape, causing the aperture 716 tobecome tapered due to the return of the top portion 702 to a concaveshape.

Referring to FIGS. 9A through 9C, the valve 700 may be formed in the topportion 702 according to the method illustrated. As shown in FIG. 9A,the sidewall 706 and top portion 702 may be formed, such as by a moldingprocess. As is apparent in FIG. 8A, the mold 900 includes mold portions900 a, 900 b combinable to form a cavity 902 that may be filled with aliquid polymer that becomes solid through a cooling or curing process.The cavity 902 may include surfaces 904 a, 904 b positioned on eitherside of the top portion 702 of the molded valved cover 700. In theillustrated embodiment, the surfaces 804 a, 804 b are planar. The moldportions 900 a, 900 b may be shaped such that the sidewall 706 aretapered or converge with distance from the top portion 702.

Referring to FIG. 9B, the aperture 716 for the valve 714 may then beformed in the top portion 702, such as by means of cutting tool 906,such as a rotating drill, punch, actuated blade, or the like. A mandrel908 may be inserted within the cavity defined by the top portion 702 andsidewall 706 and urged against the top portion 702 for support duringcutting of the aperture 716 and may then be removed to yield a valvedcover 700 such as is shown in FIG. 9C. Referring to FIG. 9B′,alternatively, the mold 900 may define a projection 910 secured to oneof the mold portions 900 a, 900 b and extending through the top portion702 during molding such that following the molding step of FIG. 9B′, theaperture 716 is already formed.

Following formation of the valved cover 700 and the aperture 716, theupper surface 704 may assume an inverted or concave shape due toresidual stresses within elastomeric polymer forming the valved cover700. For example, in the illustrated embodiment, the upper surface 704assumes a conical shape. As the upper surface 704 assumes an inverted orconcave shape, deformation of the top portion 702 may also cause theaperture 716 to assume a tapered shape such that the diameter of theaperture 716 increases with distance from the upper surface 704. In alike manner the tapering of the sidewall 706 with distance from the topportion 702 may be reduced due to narrowing of the top portion 702 dueto residual stresses within the top portion.

Referring to FIG. 10A, in an alternative method of manufacturing avalved cover 700 a mold 1000 may be used including mold portions 1000 aand 1000 b forming a cavity 1002 constraining the sidewall 706 to besubstantially perpendicular to the top portion 702. As in theembodiments described hereinabove, the cavity 1002 may be filled with aliquid polymer that is allowed to harden due to cooling or curing toform a valved cover 700. Referring to FIG. 10B, the aperture 716 for thevalve 714 of the valved cover 700 may be formed by means of a cuttingtool 1004, such as a drill, punch, articulated blade, or the like. Amandrel 1006 may be positioned within the cavity defined by the topportion 702 and sidewall 706 and resist deformation of the top portion702 during the cutting step. The mandrel 1006 may then be removed toyield a valved cover 700 such as is shown in FIG. 10C.

Referring to FIG. 10C, as with the embodiment of FIGS. 9A through 9C,cutting of the aperture 716 may result in deformation of the top portion702 due to residual stresses within the valved cover 700. Deformation ofthe top portion 702 may result in the upper surface 704 becomingconcave, such as the conical shape illustrated in FIG. 10C. Deformationof the top portion 702 may also result in the aperture 716 becomingtapered such that the diameter of the aperture 716 increases withdistance from the upper surface 704.

The residual stresses may include an interim stress differential createdbefore the formed valved cover 700 has substantially cooled. The interimstress differential may be created by, for example the temperatures ofthe molds near the valve portion 550, the thickness along the valveportion, other aspects of the mold and/or valve portion may be varied,or combinations thereof.

Referring to FIGS. 11A and 11B, a valved cover 700 having a concave orinverted upper surface 704 may be used to promote sealing with acatheter 1100 inserted through the valved cover 700 and through the hub20 and tubular portion 30 of an introducer sheath bearing the valvedcover 700. In one method of use, the catheter 1100 is inserted in adistal direction 1102 through the aperture 716 of the valve 714 andthrough the hub 20 and tubular portion 30, as shown in FIG. 11A. Thecatheter 1100 may then be drawn back slightly in proximal direction 1104such that the concavity or inversion of the upper surface 704 isreduced. Urging the catheter 1100 slightly in the proximal direction1104 may promote sealing by urging the walls of the aperture 716 againstthe catheter 1100 due to the tapered configuration of the aperture 716.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. An introducer sheath, comprising: an elongate tubular portion havinga longitudinal axis, the elongate tubular portion being elasticallydeformable about the longitudinal axis; and a hub portion, the hubportion having proximal end and a distal end, the proximal end beingsubstantially wider than the distal end and the distal end secured tothe elongate tubular portion; a valved cover elastically secured overthe proximal end of the hub portion, the valved cover defining anon-planar outer surface in a relaxed state, the outer surface definingan aperture configured to receive a medical device.
 2. The introducersheath of claim 1, wherein the hub portion and the elongate tubularportion are formed as a unitary member.
 3. The introducer sheath ofclaim 1, wherein the outer surface is substantially concave in therelaxed state.
 4. The introducer sheath of claim 1, wherein the apertureincludes a sealing surface.
 5. The introducer sheath of claim 4, whereinthe sealing surface is not generally parallel about a longitudinal axisthrough the aperture in the relaxed state.
 6. The introducer sheath ofclaim 4, wherein the sealing surface is configured to form a sealbetween the medical device and the hub in a deformed state.
 7. Theintroducer sheath of claim 1, wherein the aperture is tapered.
 8. Theintroducer sheath of claim 7, wherein the aperture has a diameter thatincreases with distance from the outer surface.
 9. A method for makingan introducer sheath assembly comprising: forming a cap having a topportion and a sidewall portion defining a cavity, the top portion havinga valve secured thereto; and inserting a proximal end of a hub portioninto the cavity, the hub portion having an elongate tubular portionsecured to a distal end thereof.
 10. The method of claim 9, whereininserting the proximal end of a hub portion into the cavity compriseselastically deforming the cap.
 11. The method of claim 9, whereinforming the cap further comprises: forming the top portion and sidewallportion; and removing a portion of the top portion to form the valve.12. The method of claim 11, wherein an upper surface of the top portionhas a concave shape, and wherein removing a portion of the top portionto form the valve further comprises: elastically deforming the topportion to decrease a concavity thereof; and removing a portion of theelastically deformed top portion to form the valve.
 13. The method ofclaim 12, wherein the valve comprises an aperture having a tapered shapewhen the top portion is in an undeformed state.
 14. The method of claim13, wherein the aperture narrows with distance from the hub portion. 15.The method of claim 14, wherein the sidewall portion extends from alower surface of the top portion.
 16. The method of claim 12, whereinelastically deforming the top portion to decrease a concavity thereofcomprises positioning an urging member within the cavity.
 17. The methodof claim 16, wherein the urging member comprises a planar upper surfaceengaging a lower surface of the top portion when the urging member ispositioned within the cavity.
 18. The method of claim 9, wherein one ofan outer surface of the hub portion and an inner surface of the sidewallportion defines a circumferential groove and the other of the outersurface of the hub portion and the inner surface of the sidewall portioncomprises a circumferential lip, the circumferential groove positionedto receive the circumferential lip when the hub portion is positionedwithin the cavity.
 19. The method of claim 18, wherein the inner surfaceof the sidewall portion is cylindrical.
 20. An assembly comprising: anelongate tubular portion having a longitudinal axis, the elongatetubular portion being elastically deformable about the longitudinalaxis; and a hub portion, the hub portion having proximal end and adistal end, the proximal end being substantially wider than the distalend and the distal end secured to the elongate tubular portion, the hubportion and elongate tubular portion defining a lumen; and a capcomprising a top portion and a sidewall portion defining a cavity sizedto elastically receive a portion of the hub portion, the cap furtherdefining a valve in fluid communication with the lumen and configured toreceive a medical device.
 21. The assembly of claim 20, wherein one ofan outer surface of the hub portion and an inner surface of the sidewallportion defines a circumferential groove and the other of the outersurface of the hub portion and the inner surface of the sidewall portioncomprises a circumferential lip, the circumferential groove positionedto receive the circumferential lip when the hub portion is positionedwithin the cavity.
 22. The assembly of claim 20, wherein an uppersurface of the top portion has a concave shape and wherein the sidewallportion extends from a lower surface of the top portion.